Extension cords, RPTs and Surge Suppressors

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j_a_wolfe

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Good afternoon all,

A discussion has started around the proverbial water cooler concerning daisy chaining of these devices. I have found one citation, OSHA's standard at 29 CFR ?1910.303(b)(2),

[Installation and use, requires that "Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling." Manufacturers and nationally recognized testing laboratories determine the proper uses for power strips. For example, the UL Directory contains instructions that require UL-listed RPTs to be directly connected to a permanently installed branch circuit receptacle; they are not to be series-connected to other RPTs or connected to extension cords.]


I have been unable to find a similar constraint in NEC and I've seen kits packaged by national manufacturers containing a RPT and an extension cord. Am I missing something?

Jim
 
j_a_wolfe said:
I have been unable to find a similar constraint in NEC and I've seen kits packaged by national manufacturers containing a RPT and an extension cord. Am I missing something?

Jim
Click to expand...

can you give us an example of such a kit?

there is no code that says you cannot supply two parts that potentially could be used in a way that violates either some code or the UL requirements for such devices.
 
petersonra said:
can you give us an example of such a kit?

there is no code that says you cannot supply two parts that potentially could be used in a way that violates either some code or the UL requirements for such devices.
Click to expand...

This is quite true. I did some additional Googling and found several (differing) descriptions telling you the proper way to use these items together. Since I found them on the internet, they must be right . . .:lol:
RPT.jpg
 
And there may be a significant difference between connecting an RPT to an extension cord and powering an extension cord from the RPT.
 
GoldDigger said:
And there may be a significant difference between connecting an RPT to an extension cord and powering an extension cord from the RPT.
Click to expand...

I'm reading the citation and it seems ambiguous:

"they are not to be series-connected to other RPTs or connected to extension cords."

Perhaps it means that they can't be plugged into an extension cord but an extension cord may be plugged into them. Splitting hairs but I've known an inspector or two that dearly loved the splitting of hairs.

Jim
 
petersonra said:
The Belkin package does not seem to even suggest they can be used together.
Click to expand...

While it doesn't say they should be used together, being packaged together would seem to imply that they could.

This discussion started around a training table requiring several laptops and a projector. Having 3 duplex receptacles located in the room, none of which were within reach of the 4 foot power strips available, we looked for a solution. A heavy duty (14ga) extension cord with a single connection was run from the receptacle to the table whereupon the power strip was plugged into it. everyone had power but the discussion started as to whether we were in violation of some code, statute or ruling and it has gone downhill from there. The reference to the CFR 129 finding was the only thing I could find but I think there must be a corresponding restriction in NFPA.

Not a big deal since the meeting lasted less time than this thread but curiosity will not be satisfied without a better citation.

Jim
 
I have thought the NEC basically stops at the outlet. Other codes may apply, such as IFC 605.4(may have been superseded), but I believe it mentioned RPT's must be plugged directly into a permanent receptacle, which addresses the daisy-chaining question. Don't recall if it mentions anything about extension cords and RPT's, but I do recall seeing some listed RPT's with various lengths of cords.
 
in that package, the strip cannot plug into the extension due to strip having 3-prong, etc. so using extension on strip is fine, but they probably dont want strip on a 3-prong extension cord ???
 
UL White Book 2013 Relocatable Power Taps (XBYS)

UL White Book 2013 Relocatable Power Taps (XBYS)

RELOCATABLE POWER TAPS (XBYS)
USE AND INSTALLATION
This category covers relocatable power taps rated 250 V ac or less, 20 A or less. They are intended for indoor use as relocatable multiple outlet extensions of a single branch circuit to supply laboratory equipment, home workshops, home movie lighting controls, musical instrumentation, and to provide outlet receptacles for computers, audio and video equipment, and other equipment.

Relocatable power taps consist of:

a) One attachment plug and a single length of flexible cord terminated in a single enclosure in which one or more receptacles may be mounted, or

b) One attachment plug and a single length of flexible cord terminated in a single enclosure in which one or more receptacles may be mounted. Up to six lengths of flexible cord, not exceeding 1-1/2 ft in length, may exit the enclosure with each length terminating in a separate, single cord connector, or

c) One attachment plug and a single length of flexible cord terminated in an enclosure in which one or more receptacles may be mounted. A second enclosure in which one or more receptacles may be mounted that is interconnected to the first enclosure with flexible cord, maximum 1-1/2 ft long, may be employed. An interconnected switch housing may also be employed to remotely control the relocatable power tap, provided that the length of the flexible cord between the enclosure and switch housing is not greater than 6 ft.

They may, in addition, be provided with fuses or other supplementary overcurrent protection, switches, suppression components and/or indicator lights in any combination, or connections for cable, communications, telephone and/or antenna.

Relocatable power taps are intended to be directly connected to a permanently installed branch circuit receptacle. Relocatable power taps are not intended to be series connected (daisy chained) to other relocatable power taps or to extension cords.

Relocatable power taps are not intended for use at construction sites and similar locations.

Relocatable power taps are not intended to be permanently secured to building structures, tables, work benches or similar structures, nor are they intended to be used as a substitute for fixed wiring. The cords of relocatable power taps are not intended to be routed through walls, windows, ceilings, floors or similar openings.

The length of the power-supply cord, as measured from the outside surface of the enclosure of the relocatable power tap to the plane of the face of the attachment plug, should not exceed 25 ft (7.62 m) nor be less than
1.5 ft (0.46 m).

Relocatable power taps have not been investigated and are not intended for use with general patient care areas or critical patient care areas of health care facilities as defined in Article 517 of ANSI/NFPA 70, ??National Electrical Code.??
 
FionaZuppa said:
in that package, the strip cannot plug into the extension due to strip having 3-prong, etc. so using extension on strip is fine, but they probably dont want strip on a 3-prong extension cord ???
Click to expand...

Just to muddy the waters, this is a quote from the ICC:

"605.5.1 Power supply.

Extension cords shall be plugged directly into an approved receptacle, power tap or multiplug adapter and, except for approved multiplug extension cords, shall serve only one portable appliance."
 
Isn't is interesting that you cannot plug an RPT into an extension cord (or even plug a cube tap into an extension cord) but you can use a three-headed extension cord with each appliance cord plugged in directly.
Among other things, no extra voltage drop or localized heating from the closely spaced multiple connections per appliance.
 
One of my 3000 sq ft office/shop/warehouses got a surprise visit from local city fire marshal.... We flunked big time for using extension cords! NOt allowed at all in commercial buildings in this city.... BUT - those power strips are fine! AND in case the power strip cord is too short, it is fine to plug power strip into another power strip into another power strip into.... as many times as needed!
 
mike_kilroy said:
One of my 3000 sq ft office/shop/warehouses got a surprise visit from local city fire marshal.... We flunked big time for using extension cords! NOt allowed at all in commercial buildings in this city.... BUT - those power strips are fine! AND in case the power strip cord is too short, it is fine to plug power strip into another power strip into another power strip into.... as many times as needed!
Click to expand...

And that's exactly where you find the restrictions. In the Life Safety Code and the Fire Prevention Code aside from what UL & the NEC say. I had started digging on it for a thread a couple weeks ago but didn't get it done. I'll get back on it or someone else can look it up.

The main thing is that an extension cord can not be used for permanent wiring. You need to install a receptacle.

Anything that creates multiple receptacles must have an OCPD. No OCPD on your power strip means it's not allowed.
 
mgookin said:
And that's exactly where you find the restrictions. In the Life Safety Code and the Fire Prevention Code aside from what UL & the NEC say. I had started digging on it for a thread a couple weeks ago but didn't get it done. I'll get back on it or someone else can look it up.

The main thing is that an extension cord can not be used for permanent wiring. You need to install a receptacle.

Anything that creates multiple receptacles must have an OCPD. No OCPD on your power strip means it's not allowed.
Click to expand...

RELOCATABLE POWER TAPS (XBYS)
USE AND INSTALLATION
....
They may, in addition, be provided with fuses or other supplementary overcurrent protection, switches, suppression components and/or indicator lights in any combination, or connections for cable, communications, telephone and/or antenna.
....

No OCPD required in White Book.

NFPA 1-2009 11.1.7.* -- no requirement for OCPD

NFPA 101-2009 -- no reference to Extension cords found.
 
mgookin said:
Anything that creates multiple receptacles must have an OCPD. No OCPD on your power strip means it's not allowed.
Click to expand...

iwire said:
Are you sure about that?

https://www.legrand.us/wiremold/at-...lugmold-multi-outlet-strips.aspx#.U7VRyEBhsTA
Click to expand...

mgookin said:
View attachment 10551
From NFPA 1
Click to expand...

The device I posted creates multiple receptacles and does not have OCP.

The NFPA 1 sections you posted do not apply to it as it is not a 'relocatable power tap'
 
mgookin said:
Anything that creates multiple receptacles must have an OCPD. No OCPD on your power strip means it's not allowed.
Click to expand...

Current Taps and Adapters (commonly referred to as power cubes) provide multiple receptacles and are available without OCPD. They are listed under UL 498A, UL Standard for Safety for Current Taps and Adapters. The scope of this standard explains how it relates to other multioutlet devices like RPT's and cord connected devices.

1 Scope

1.1 These requirements cover current taps and adapters for use in accordance with the National
Electrical Code, ANSI/NFPA-70.

1.2 These requirements do not cover current taps or adapters rated at more than 200 A or for more than
600 V. See 6.1.

1.3 These requirements do not directly apply to current taps wired to flexible cord or lampholder adapters
but supplement the applicable standards. Lampholder adapters are covered in the Standard for
Lampholders, UL 496. Current taps wired to flexible cord are covered in the Standard for Attachment
Plugs and Receptacles, UL 498.

1.4 These requirements do not cover cord-connected, relocatable power taps intended only for indoor
use as a temporary extension of a grounding, alternating-current branch circuit for general use, and which
are covered by the Standard for Relocatable Power Taps, UL 1363.

1.5 These requirements do not cover the current or voltage conversion circuitry capable of being used in
travel adapters.

1.6 As used in this Standard, the term device is intended to refer to both current taps and adapters unless
specifically stated otherwise.
 
Oh what a web we weave when we look at NFPA 1, 70, & 101, & UL White Book

Oh what a web we weave when we look at NFPA 1, 70, & 101, & UL White Book

** OP asks if OSHA 29 CFR ?1910.303(b)(2) requires us to install use equipment according to a NRTL's listing, does the NEC have such a restriction?

* This is a question we never answer, by-the-way. So I'll do it now.

90.7 Examination of Equipment for Safety. For specific items of equipment and materials referred to in this Code, examinations for safety made under standard conditions provide a basis for approval where the record is made generally available through promulgation by organizations properly equipped and qualified for experimental testing, inspections of the run of goods at factories, and service-value determination through field inspections. This avoids the necessity for repetition of examinations by different examiners, frequently with inadequate facilities for such work, and the confusion that would result from conflicting reports on the suitability of devices and materials examined for a given purpose.

This is how NEC refers to UL (and other NTRLs?]

110.3 Examination, Identification, Installation, and Use of Equipment.
(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

This is how the NRTL and installation rules are incorporated into the NEC.

** reference to packages that contain both a RTP and an extension cord

** I thought NEC stopped at the outlet [receptacle].

* see Article 400 (400.7 & 400.8)

** XBYS from White Book

* directly connected to a permanently installed branch circuit receptacle. [they are to plug into a "wall" receptacle]
* are not intended to be series connected (daisy chained) to other relocatable power taps or to extension cords. [RTPs and extension cords are not to be plugged into each other]

** ICC 605.5.1 allows daisy chaining

** Local inspector found daisy chaining OK.

** NFPA 1 Fire Prevention Code

* NFPA 1-2009 11.1.6.1 need a OCPD in an RTP.
[* NFPA 1-2009 11.1.4 requires abandoned wiring to be tagged or removed which is more restrictive than NEC]

** NFPA 101 Life Safety?

** Counter example -- corded WireMold receptacle strip (W/M 2000) with UL and without OCPD

** NPFA 1 11.1.6.1 RTP requires OCPD

** UL 498A UL 1363 -- no answer to the OCPD question

SO the summary of all this? NFPA 1 and UL XBYS are not perfectly co-ordinated; and NFPA 1 and NEC are not perfectly co-ordinated [NFPA 1 11.1.4]
 
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